Ments



Patented Apr. 16, 1929.

UNITED STATES PATENT. OFFICE.

MICHELE BLANCATO, OF PARIS, FRANCE, ASSIGNOR, BY DIRECT AND MESNE ASSIGDL MENTS, TO KENT-BLANCATO COMPANY, INC., A CORPORATION OF NEW YORK.

COATING COMPOSITION.

No Drawing. Application filed May'2,

The object of my invention is the production of a quick drying solution to be applied to the sensitized side of cinematograph films, positive or negative, or to otherfilms of cellulosic composition, in order to protectthem from deterioration through water, grease, dirt, or physical injury; to be applied to the surface of photographic prints, books, documents, and paper of all kinds, with or without imprint, handwriting or design, in or der to protect them from humidity, stains and dirt, and preserve them from the fading and damage caused by contact with the air; to be applied to the surface of bonds, checks, and other papers of value or importance to prevent falsification or forgery; or to be applied to other surfaces or material for protection, waterproofing or to secure wasl1- ability.

The coating formed by the solution incorporates itself intimately with the stratum to which it is applied; it is durable,transparent, highly flexible, and washable with cold or warm water. It can be applied by rubbing, painting, spraying, or by any other suitable device.

As a consequence of the nature of the gelatine and of the sensitized layer, photographic and motion picture films are subject to change and deterioration if kept in a damp place, and if water or other liquid should chance to spill on the reel, the swelling of the intermediate layers causes the printed side to adhere firmly ta the superimposed side, with consequent spoiling of the photographs. It also requires the greatest attention in handling, because the developed layer, although dry, is very easily stained; greasy hands, the tin container, the projection machine, the operation of winding on the reels, dust, etc, all contribute to the gradual loss of that degree of cleanliness indispensable to perfect projection, and instead there forms a layer of dirt of greater or less thickness.

It also often happens that during the projection or winding of the film 011 the reels, the printed side, that is, the side with the silver coating, is scratched by a sharp point of some kind, leaving a streak that diminishes or destroys the value of the film, for the streak is reproduced magnified on the screen.

To eliminate such drawbacks I have invented a coating composition to cover and protect the printed side with a thin, durable, very flexible, intimately adherent and trans parent coating, without causing the silver salts or the gelatine to undergo any alteration or modification in their structure that would affect the transparency and flexibility of the film, which remains absolutely unaltered.

lVhen coated with my solution the film does not present any difference in appearance from any other, whilst it has the advantages:

1. Of being washable at any time with cold or warm water to remove any dirt or stains, and dryable with a piece of fabric, for the side with the silver coating is protected by a strong, durable, and yet flexible layer, that incorporates with it and preserves itindefinitely.

2. Of resisting pressure from a sharp point, thus preventing streaks in the sensitized layer; however should the pressure be so great as to scratch through the layer, this can be immediately remedied by applying to the scratch itself the necessary amount of solution to fill it, so that no deterioration of the film will result.

Besides serving for the protection and conservation of films, my coating composition can be applied to many other uses:

Applied to any kind of paper, it incorporates with it, forming at the surface an extremely fine layer that permits of its being washed, thus permitting of the paper being kept free of dust, spots, etc. It is thus possible to preserve indefinitely documents and other papers, and prevent their fading from time and exposure. 7

Applied to a photographic print on paper, the print will retain its color permanently, no oxidation being possible.

Applied to wall paper or other paper containing designs, the surface may be washed when necessary, without any fading of the colors, or any other alteration whatever.

Applied to paper money, bonds, negotiable documents and other papers of value, to wills and other documents of importance, it prevents falsification or forgery, for the solution becomes embodied in the sheet, forming at the surface an extremely fine, uniform and flexible layer, which is perfectly transparent. It becomes incorporated with the paper, and it is impossible to remove the print or writing in any way, for any other substance introduced to effect falsification would cause only the spoiling of thesheet, it not being, possible to dissociate the solution from the paper.

The coating composition is made lows:

'lransparent celluloid or similar pyroxylin is preferably first exposed to a variable ten'iperature of from about to C. for sufficient time to dry it as much as possible. The celluloid is then immersed in acetic acid ((3H,.CO0H) in a closedcontainer and agitated, these ingredients being inthe variable proportion of about 1 gram of celluloid to 2 to elcubic centimeters of liquid-acetic acid. The acetic acid and the celluloid are stirred by means of an internal agitator for a period varying from about 20 to minutes. Then acetone (CH QOCH is added in the vari able proportions of 8 to 12 cubic centimeters to 1 gram of the celluloid. The agitation is continued in the closed container, opening vents from time to time for the escape of vapors, until a syrup-like mass is formed which has the tendency of becoming thicker. When the celluloid is completely dissolved, the mixture is agitated while ethyl sulfate (SOAC HQ is added in the proportion of about 1 to 2 cubic centimeters for every gram of celluloid Next there is added a solution of n'iagnesium chloride (MgCL -t 611 C), consisting of chloride of magnesium dissolved in alcohol in the variable proportion of 20 to 35 grams for every thousand cubic centimeters of alcohol, approximately 1 to 2 cc. of this solution is used for each gram of the celluloid. To the continuouslyagitated mixture amyl acetate (C H C ILQ is then added. in the proportion of about 10 to 16 cc. for each gram of dissolved celluloid, the vents of the receptacle being opened at intervals for brief periods as before in order to permit ga is to escape. Finally, ethyl other as fol- (Q ,.O.C,.l l,) is.added in the proportion of l to 2 cc. for each gram of celluloid. The

mixture is continuously agitated for another hour, and then filtered undercover, after which the coating composition is ready for use.

The use of acetic acid is preferred because of its corrosive action on celluloid, by virtue of which it greatly promotes the solvent actionof the acetone. Amyl acetate, which is a well known solvent for pyroxylin, incorpoi-ates and blends the different ingredients and makes the liquid clearer.

The ethyl sulfate, the use of which is an important feature of the invention, has a number of functions in the coating composition. It makes and keeps the solution transparent and prevents the dissolved celluloid taking on an opacity or ashy color. When acetic acid is used, it also neutralizes the further corrosive action of that lngredient. A

fluid and quick-dryin very important effect, however, of the ethyl sulfateis greatly to increase the molecular elasticity of the coatings which are obtained. Ethyl ether makes the composition more and in combination with the ethyl sulfate contributes to the flexibility and elasticity of the thin protective coatings. In this connection it develops or increases the action of-the ethyl sulfate.

The chloride of magncsiun'i is a fire-proofin ingredient to render the coatings noninflammable or to neutralize or greatly reduce the intlammability thereof. For the solution of chloride of magnesium a solution of biborate of sodium (li Na O l-lOll o) in heated distilled water to 15 grams of biborate of sodium to 100 cc. of Water) can be substituted, but in this case acetic acid should not be employed as biborate of sodium with acetic acid would produce turbidity in the composition. Instead of the acetic acid, its homolog, ethyl alcohol (C H OH), can be substituted, adding to the latter half its volume of ethyl sulfate. Instead of the ethyl ether, the same quantity of amyl ether (C T OC H can be substituted, adding to the latter half its volume of methyl propyl ether (CH OCJL).

Vi hat I claim as new is:

1. A pyroxylin coating composition con taining ethyl sulfate.

2. Apyroxylin coating composition containing ethyl sulfate and an ether.

A coating composition comprising celluloid dissolved with the aid of acetic acid and acetone and containing ethyl sulfate.

l. A coating composition comprising celluloid dissolved with the aid of acetic acid and acetone and containing ethyl sulfate and an ether.

5. A coating composition made of colluloid, solvents including acetic acid, acetone, and amyl acetate, and ethyl sulfate.

6. A coating composition made of celluloid, solvents including acetic acid, acetone, and amyl acetate, ethyl sulfate and an ether.

7. A coating composition made of celluloid, solvents including acetic acid, acetone, and amyl acetate, magnesium chloride and ethyl sulfate.

8. A coating composition made of celluloid, solvents including acetic acid, acetone, and amyl acetate, magnesium chloride, ethyl sulfate and ether.

9. The method of preparing a coating composition which comprises dissolving celluloid in acetic acid and acetone, thereafter adding ethyl sulfate, magnesium chloride, and ainvl acetate.

10. The method of preparing a coating 1 

